(~s)
1.
A ~ is a place or situation in which people or ideas of different kinds gradually get mixed together.
The republic is a ~ of different nationalities.
N-COUNT: usu sing
2.
If something is in the ~, you do not know what is going to happen to it. (mainly BRIT)
Their fate is still in the melting-pot.
PHRASE: v-link PHR, PHR after v